Siemens SIMATIC S7-1500 and S7-1200 Use After Free (CVE-2021-22901)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(503086);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/13");

  script_cve_id("CVE-2021-22901");
  script_xref(name:"ICSA", value:"23-348-10");

  script_name(english:"Siemens SIMATIC S7-1500 and S7-1200 Use After Free (CVE-2021-22901)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"curl 7.75.0 through 7.76.1 suffers from a use-after-free vulnerability
resulting in already freed memory being used when a TLS 1.3 session
ticket arrives over a connection. A malicious server can use this in
rare unfortunate circumstances to potentially reach remote code
execution in the client. When libcurl at run-time sets up support for
TLS 1.3 session tickets on a connection using OpenSSL, it stores
pointers to the transfer in-memory object for later retrieval when a
session ticket arrives. If the connection is used by multiple
transfers (like with a reused HTTP/1.1 connection or multiplexed
HTTP/2 connection) that first transfer object might be freed before
the new session is established on that connection and then the
function will access a memory buffer that might be freed. When using
that memory, libcurl might even call a function pointer in the object,
making it possible for a remote code execution if the server could
somehow manage to get crafted memory content into the correct place in
memory.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.");
  script_set_attribute(attribute:"see_also", value:"https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf");
  script_set_attribute(attribute:"see_also", value:"https://cert-portal.siemens.com/productcert/pdf/ssa-732250.pdf");
  script_set_attribute(attribute:"see_also", value:"https://cert-portal.siemens.com/productcert/html/ssa-398330.html");
  script_set_attribute(attribute:"see_also", value:"https://support.industry.siemens.com/cs/ww/en/view/109808678");
  script_set_attribute(attribute:"see_also", value:"https://support.industry.siemens.com/cs/ww/en/view/109811116/");
  script_set_attribute(attribute:"see_also", value:"https://support.industry.siemens.com/cs/ww/en/view/109812218");
  script_set_attribute(attribute:"see_also", value:"https://support.industry.siemens.com/cs/ww/en/view/109806100/");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-22901");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_cwe_id(416);

  script_set_attribute(attribute:"vuln_publication_date", value:"2022/03/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/03/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/03/13");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_cp_1242-7_v2_firmware:3.3.46");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_cp_1243-1_firmware:3.3.46");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_cp_1243-7_lte_eu_firmware:3.3.46");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_cp_1243-7_lte_us_firmware:3.3.46");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_cp_1243-8_irc_firmware:3.3.46");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_cp_1543-1_firmware:3.0.22");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_cp_1545-1_firmware:1.1");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_net_cp_1242-7_v2_firmware:3.3.46");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_net_cp_1543-1_firmware:3.0.22");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_s7-1200_cp_1243-1_firmware:3.3.46");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_s7-1200_cp_1243-1_rail_firmware:3.3.46");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.5");
  script_set_attribute(attribute:"generated_plugin", value:"former");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Tenable.ot");

  script_copyright(english:"This script is Copyright (C) 2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("tenable_ot_api_integration.nasl");
  script_require_keys("Tenable.ot/Siemens");

  exit(0);
}


include('tenable_ot_cve_funcs.inc');

get_kb_item_or_exit('Tenable.ot/Siemens');

var asset = tenable_ot::assets::get(vendor:'Siemens');

var vuln_cpes = {
    "cpe:/o:siemens:simatic_cp_1545-1_firmware:1.1" :
        {"versionEndExcluding" : "1.1", "family" : "S71500", "orderNumbers" : ['6GK7545-1GX00-0XE0']},
    "cpe:/o:siemens:simatic_cp_1543-1_firmware:3.0.22" :
        {"versionEndExcluding" : "3.0.22", "family" : "S71500", "orderNumbers" : ['6GK7543-1AX00-0XE0']},
    "cpe:/o:siemens:siplus_net_cp_1543-1_firmware:3.0.22" :
        {"versionEndExcluding" : "3.0.22", "family" : "S71500", "orderNumbers" : ['6AG1543-1AX00-2XE0']},
    "cpe:/o:siemens:simatic_cp_1242-7_v2_firmware:3.3.46" :
        {"versionEndExcluding" : "3.3.46", "family" : "S71200", "orderNumbers" : ['6GK7242-7KX31-0XE0']},
    "cpe:/o:siemens:simatic_cp_1243-1_firmware:3.3.46" :
        {"versionEndExcluding" : "3.3.46", "family" : "S71200", "orderNumbers" : ['6GK7243-1BX30-0XE0']},
    "cpe:/o:siemens:simatic_cp_1243-7_lte_eu_firmware:3.3.46" :
        {"versionEndExcluding" : "3.3.46", "family" : "S71200", "orderNumbers" : ['6GK7243-7KX30-0XE0']},
    "cpe:/o:siemens:simatic_cp_1243-7_lte_us_firmware:3.3.46" :
        {"versionEndExcluding" : "3.3.46", "family" : "S71200", "orderNumbers" : ['6GK7243-7SX30-0XE0']},
    "cpe:/o:siemens:simatic_cp_1243-8_irc_firmware:3.3.46" :
        {"versionEndExcluding" : "3.3.46", "family" : "S71200", "orderNumbers" : ['6GK7243-8RX30-0XE0']},
    "cpe:/o:siemens:siplus_net_cp_1242-7_v2_firmware:3.3.46" :
        {"versionEndExcluding" : "3.3.46", "family" : "S71200", "orderNumbers" : ['6AG1242-7KX31-7XE0']},
    "cpe:/o:siemens:siplus_s7-1200_cp_1243-1_firmware:3.3.46" :
        {"versionEndExcluding" : "3.3.46", "family" : "S71200", "orderNumbers" : ['6AG1243-1BX30-2AX0']},
    "cpe:/o:siemens:siplus_s7-1200_cp_1243-1_rail_firmware:3.3.46" :
        {"versionEndExcluding" : "3.3.46", "family" : "S71200", "orderNumbers" : ['6AG2243-1BX30-1XE0']},
    "cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5" :
        {"versionEndExcluding" : "3.1.5", "versionStartIncluding" : "3.1.0", "family" : "S71500", "orderNumbers" : ['6ES7518-4FX00-1AB0', '6ES7518-4AX00-1AB0', '6ES7518-4FX00-1AC0', '6ES7518-4AX00-1AC0']},
    "cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.5" :
        {"versionEndExcluding" : "3.1.5", "versionStartIncluding" : "3.1.0", "family" : "S71500", "orderNumbers" : ['6AG1518-4AX00-4AC0']}
};

tenable_ot::cve::compare_and_report(asset:asset, cpes:vuln_cpes, severity:SECURITY_HOLE);